The influence of the distribution system structure on distortion emission and propagation

This paper presents an investigative approach for studying the influence of power distribution system structure on system sensitivity in the scope of harmonic distortion. Thereby, a method based on eigenvalue decomposition of the nodal admittance matrix is introduced in order to find weak nodes of the power system. An illustrative example explains the basic properties of the method. Furthermore, a real distribution network is modeled, where some measurements have been carried out to reflect in the admittance matrix the real relation between connected loads. Applying the method to the studied network it is shown that the system structure changes introduced by the method can improve the system sensitivity at a chosen harmonic order. Moreover, it is shown that harmonic elimination at one point of the network does not always lead to improved reliability in whole system. It is found that the eigenvalue decomposition approach gives very promising results in the scope of finding weak nodes and branches in a system with regard to harmonic distortion.